From personal experience, this is easily the best that I've ever owned:http://www.newegg.com/Product/Product.aspx?Item=N82E16833315041
It isn't Wireless-N, but even now it's still the fastest thing I've ever used. It has great range/signal reception, and will do basically anything you ask it to. I'm sure someone could find you something faster, but it's definately a great deal for $20.
If you need a lot of sheer speed and have a wireless-n router, then I'd go for what rolli suggested. I don't think it has quite as much range, but would be faster if your router + ISP are capable of pulling those speeds.
You'll have to excuse my stupidity, I just read the part about what router you have... my bad...
Feel free to ignore anything I've said up to this point.
I'd probably go with that Asus. http://www.newegg.com/Product/Product.aspx?Item=N82E16833156054
That's an option too, if you want to pay a little more... I have absolutely no clue how it would perform, though...